Flavonoid glycosides and their putative human metabolites as potential inhibitors of the SARS-CoV-2 main protease (Mpro) and RNA-dependent RNA polymerase (RdRp)

BACKGROUND Since the World Health Organization (WHO) declared Coronavirus disease 2019 (COVID-19) to be a pandemic infection, important severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) non-structural proteins (nsp) have been analysed as promising targets in virtual screening approaches. Among these proteins, 3-chymotrypsin-like cysteine protease (3CLpro), also named main protease, and the RNA-dependent RNA polymerase (RdRp), have been identified as fundamental targets due to its importance in the viral replication stages. OBJECTIVES To investigate, in silico, two of the most abundant flavonoid glycosides from Dysphania ambrosioides; a medicinal plant found in many regions of the world, along with some of the putative derivatives of these flavonoid glycosides in the human organism as potential inhibitors of the SARS-CoV-2 3CLpro and RdRp. METHODS Using a molecular docking approach, the interactions and the binding affinity with SARS-CoV-2 3CLpro and RdRp were predicted for quercetin-3-O-rutinoside (rutin), kaempferol-3-O-rutinoside (nicotiflorin) and some of their glucuronide and sulfate derivatives. FINDINGS Docking analysis, based on the crystal structure of 3CLpro and RdRp, indicated rutin, nicotiflorin, and their glucuronide and sulfate derivatives as potential inhibitors for both proteins. Also, the importance of the hydrogen bond and π-based interactions was evidenced for the presumed active sites. MAIN CONCLUSIONS Overall, these results suggest that both flavonoid glycosides and their putative human metabolites can play a key role as inhibitors of the SARS-CoV-2 3CLpro and RdRp. Obviously, further researches, mainly in vitro and in vivo experiments, are necessary to certify the docking results reported here, as well as the adequate application of these substances. Furthermore, it is necessary to investigate the risks of D. ambrosioides as a phytomedicine for use against COVID-19.

Medicinal and toxic plants from Muribeca Alternative Health Center (Pernambuco, Brazil): an ethnopharmacology survey / Plantas medicinales y tóxicas del Centro de Salud Alternativa de Muribeca (Pernambuco, Brasil): un análisis etnofarmacológico

Forty-four medicinal species are cultivated at CESAM (Muribeca Alternative Health Center). The most frequent uses cited are related to the respiratory, digestive, and nervous systems. The phytotherapics most sold at CESAM, based on Justicia pectoralis var. stenophylla and Petiveria alliacea, are listed as toxic. In addition to these, eight other species are noted by specialists as toxic. A procedure to minimise the undesirable effects of such plants is also described.

Cuarenta y cuatro especies medicinales son cultivadas en CESAM (Muribeca Centro de Salud Alternativa). Los usos más frecuentes están relacionados con los aparatos respiratorio, digestivo y nervioso. Las hierbas más vendidas en CESAM, basadas en Justicia pectoralis var. stenophylla y Petiveria alliacea, también se consideran tóxicas. Además de éstas, otras ocho especies son identificadas por los especialistas del CESAM como tóxicas. En éste estudio, también se describe un procedimiento para reducir al mínimo los efectos indeseables de éstas plantas.

Stability of Tilo ® tablets formulation obtained from dry extract of Justice pectoralis Jacq

Justicia pectoralis Jacq., Acanthaceae, is a herb known popularly in Cuba as Tilo and used traditionally as sedative. The development in a solid pharmaceutical (Tablets 100 mg) using dry extract of Justicia pectolaris aqueous extract is of interest for the development of phytomedicines, which uses this active raw material. The aim of the present study was to carry out chemical and biological stability studies to the formulation. A method of coumarin determination by High Performance Liquid Chromatography (HPLC) was used and validated. The stability studies during different periods of time (24 months) showed a stability of the product stored at 32 ± 2 °C, and protected of the light.

Justicia pectoralis Jacq., Acanthaceae é uma erva conhecida popularmente em Cuba como Tilo e utilizada tradicionalmente como sedativo. O desenvolvimento de formas farmacêuticas sólidas (comprimido 100 mg) usando extrato aquoso seco de J. pectoralis é de interesse no desenvolvimento de fitoterápicos que empreguem esse princípio ativo. O objetivo do presente estudo foi realizar estudos de estabilidade químicos e biológicos da formulação. Um método de determinação de cumarinas por Cromatografia Líquida de Alta Eficiência (CLAE) foi usado e devidamente validado. Os estudos de estabilidade durante diferentes períodos de tempo (24 meses) mostraram a estabilidade do produto preservado a 32 ± 2 °C e protegido da luz.

Phytomedicines of Sickle Cell Crisis in Mezam Division, Cameroon: Preventive and Curative Cares.

Background: The aim of this study was to survey the Mezam Division of Cameroon, with a view to documenting how the population of that area treat sickle cells disease using medicinal plants, and to determine the need for further information on sickle cell disease or sickle cell anaemia in that division. Method: Two questionnaires (one to patients and the other to traditional healers) were designed to gather information on every day life of patients and their parents, and medicinal plants were collected during the field trips. Results: Seventeen plants species belonging to 16 genera and 13 families were collected. They formed 12 recipes used to treat sickle cell by 5 traditional healers. With the help of these phytotherapists, we meet 92 former and new patients aged from 1 to 35 years old. The current symptoms of the disease were anaemia, hand and foot syndrome, splenomegaly and rheumatic pains. A rate of 52.2% of patients felt better after the treatment; 19.5% of patients with ongoing treatment, felt persistent symptoms; and 28.3% abandoned the treatment. Conclusion: Two haemoglobin diseases rage in Mezam Division and present some standard clinic demonstrations of anaemia hemolytic: HbS/S and HbS/C. The therapeutic preparations with Zanthoxylum zanthoxyloides exert an influence over haematopoietic organs like the spleen, by a dedifferentiation of its cells, and the production of Hb(α2, ү2) which is the foetal haemoglobin. Thus the patient haemoglobins are S/S and F. This was observed in a patient aged 26 years old in 1999. Since that year, she is still symptom-free up to 2011. The main limitation of this research, however, may be used as a direction for future research, which is, assessing the results from the field at the chemical level in laboratories.

Passiflora incarnata treatment during gestation and lactation: toxicological and antioxidant evaluation in wistar dams

Passiflora incarnata is marketed in many countries as a phytomedicine. Even though the directions of most marketed phytomedicines recommend them to be used under medical supervision, reproductive and developmental studies are sparse and not mandatory for regulatory purposes. In this study, a reproductive toxicity evaluation of P. incarnata was conducted in Wistar rats gavaged (30 or 300 mg/kg) during pregnancy and lactation. Moreover, considering that antioxidant properties have been attributed to flavonoids present in the genus Passiflora, it was also evaluated the antioxidant/pro-oxidant balance in the plasma of these dams and the antioxidant potential in an in vitro test. P. incarnata treatment did not influence dams´ body weight as well as reproductive (gestation length, post-implantation loss, litter size, litter weight) and hepatic (albumin, AST, ALT, GGT) parameters. The antioxidant property of P. incarnata was evidenced both in vivo (increase in the total antioxidant plasmatic potential) and in vitro (decrease in neutrophil-induced respiratory burst). The results from the present study indicate that under the experimental conditions evaluated, P. incarnata treatment during gestation and lactation presented antioxidant activity in the absence of maternal reproductive toxicity.

Passiflora incarnata é comercializada em muitos países como fitoterápico. Embora a bula da maioria dos fitoterápicos recomende que eles sejam usados sob supervisão médica, estudos sobre a toxicidade reprodutiva e do desenvolvimento desses produtos são raros e não obrigatórios para fins regulatórios. Neste estudo, realizamos uma avaliação da toxicidade reprodutiva da P. incarnata, administrada a ratas Wistar (30 ou 300 mg/kg, gavagem) durante a gestação e a lactação. Além disso, considerando as propriedades antioxidantes que têm sido atribuídas aos flavonoides presentes no gênero Passiflora, também avaliou-se o equilíbrio antioxidante/pró-oxidante no plasma destas fêmeas e conduziu-se um teste in vitro para avaliar o potencial antioxidante. O tratamento com P. incarnata não influenciou o peso corporal das fêmeas, bem como indicadores de toxicidade reprodutiva (perdas pós-implantação, número de filhotes vivos e peso da ninhada) e os parâmetros de função hepática (albumina, AST, ALT, GGT). A propriedade antioxidante da P. incarnata foi evidenciada tanto in vivo (aumento do potencial antioxidante total plasmático) quanto in vitro (diminuição do burst respiratório em neutrófilos). Os resultados deste estudo indicam que, nas condições experimentais avaliadas, o tratamento com P. incarnata durante a gestação e lactação apresentou efeito antioxidante, na ausência de toxicidade reprodutiva materna.

Phytotherapy in Brazil: recovering the concepts

This article shows the evolution of the Brazilian legislation in recent years in the area of herbal products and discusses the concept of phytotherapy in Brazil, bringing information about how it works in Europe.

Phytosomal Drug Delivery Systems.

Certain of the water-soluble flavonoid molecules can be converted into lipid-compatible molecular complexes, aptly called phytosomes. Phytosomes are better able to transition from a hydrophilic environment into the lipid-friendly environment of the outer cell membrane, and from there into the cell, finally reaching the blood. The term "phyto" means plant while "some" means cell-like. Phytosome is a complex of a natural active ingredient and a phospholipid. It is claimed that phytosome increases absorption of "conventional herbal extracts" or isolated active principles. The phytosome process is that combines herbal extracts and soybean phospholipids (lecithin). phytosomes are created when the standardized extract and active ingredients of a herb are bound to the phospholipids on a molecular level. The newly created Phytosome structures contain the active ingredients of the herb surrounded by the phospholipids. The phospholipid molecular structure includes a water-soluble head and two fat-soluble tails. Because of this dual solubility, the phospholipid acts as an effective emulsifier. The newly created phytosome structures contain the active ingredients of the herb surrounded by the phospholipids. The phospholipid molecular structure includes a water-soluble head and two fat-soluble tails. Because of this dual solubility, the phospholipid acts as an effective emulsifier. An emulsifier is a material that can combine two liquids that normally will not mix well together. By combining the emulsifying action of the phospholipids with the standardized botanical extracts, the phytosome form provides dramatically enhanced bioavailability and delivers faster and improved absorption of the active constituents of the herb in the intestinal tract.

Herbs of interest to the Brazilian Federal Government: female reproductive and developmental toxicity studies

In 2009 the Brazilian Ministry of Health published a document named RENISUS that lists 71 herbs traditionally used in Brazil that could result in phytomedicines to be dispensed by the governmental health care program. This manuscript reviews female reproductive and/or developmental toxicity information of these herbs. More than half (35) of the herbs lack information regarding female reproductive and/or developmental effects. From the fourteen herbs used traditionally to disturb female reproduction, five present experimental data corroborating their actions as abortifacients (Maytenus ilicifolia, Momordica charantia, Plectranthus barbatus, Ruta graveolens) or labour facilitator (Bidens pilosa). For 23 of the herbs evaluated experimentally for any type of female reproductive endpoint, only a single study was retrieved and at least twelve of these studies were conducted with a single dose. This scenario suggests that the scientific power of the published information is very low and that a scientifically-based risk/benefit analysis about the use of these herbs during pregnancy is not possible. Considering the appeal that phytomedicines have for pregnant women, usually aware and afraid of the risks that synthetic drugs may have in their pregnancy and progeny, well designed studies evaluating reproductive and/or developmental toxicity of these herbs urge.

Determinação espectrométrica dos flavonóides das folhas de Maytenus (Celastraceae) e de Passiflora (Passifloraceae) e comparação com método CLAE-UV / Spectrometric determination of flavonoids from Maytenus (Celastraceae) and Passiflora (Passifloraceae) leaves and comparison with an HPLC-UV method

Este trabalho apresenta uma modificação dos procedimentos descritos nas Farmacopéias Francesa e Européia para a análise de flavonoides de Passiflora incarnata L., Passifloraceae, por espectrometria UV-Visível e propõe a sua aplicação na determinação dos flavonoides totais das folhas da espinheira-santa (Maytenus aquifolium Mart. e Maytenus ilicifolia (Schrad.) Planch., Celastraceae) e do maracujá (Passiflora edulis Sims. e Passiflora alata Curtis, Passifloraceae). Os resultados obtidos por espectrometria no UV-Visível foram comparados aos obtidos por cromatografia líquida de alta eficiência (CLAE-UV), encontrando-se resultados estatisticamente similares entre os métodos espectrométrico modificado da Farmacopéia Francesa e CLAE-UV.

This paper reports on a modification of the spectrometric procedures originally described in the French and European Pharmacopoeia for the analysis of Passiflora incarnata L. (Passifloraceae) flavonoids, proposing its application in the determination of total flavonoids from "espinheira-santa" (Maytenus aquifolium Mart. and Maytenus ilicifolia (Schrad.) Planch., Celastraceae) and "maracujá" leaves (Passiflora edulis Sims and Passiflora alata Curtis, Passifloraceae). A comparison was made of the results obtained by the spectrometric procedure with those obtained by high performance liquid chromatography (HPLC-UV), which demonstrated complete compatibility between the modified French Pharmacopoeia (spectrometric) and HPLC-UV methods.

Plant-derived antimalarial agents: new leads and efficient phythomedicines: part 1: Alkaloids

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.

A malária ainda é um dos mais sérios problemas de saúde pública e a principal causa de mortalidade e morbidade nas regiões endêmicas. O Brasil está entre os 30 países com maior incidência de malária e a maior parte dos casos ocorre na Amazônia Legal. Novos agentes terapêuticos são necessários para o tratamento da malária. Muitas espécies vegetais são utilizadas na medicina tradicional de vários países endêmicos mas é relativamente reduzido o número daquelas que já foram investigadas quanto à sua atividade antimalárica. Menor ainda é o número de espécies das quais foram isoladas substâncias ativas e tiveram sua toxidade determinada. Esta área de pesquisa é, portanto, de alta relevância. Um projeto de descoberta de produtos naturais antimaláricos a partir de plantas de uso tradicional deve incluir ensaios in vitro e in vivo bem como o isolamento biomonitorado de substâncias ativas. Os produtos finais serão substâncias naturais antimaláricas, potenciais fármacos ou protótipos para o desenvolvimento de novos fármacos, e/ou extratos padronizados, com atividade antimalárica, os quais são necessários para estudos pré-clínicos e clínicos quando o objetivo é o desenvolvimento de fitoterápicos (fitomedicamentos) eficazes e seguros. A presente revisão discute estas duas abordagens, apresenta resumidamente as metodologias de bioensaios para avaliação de atividade antimalárica e focaliza a atividade de alcalóides pertencentes a diferentes classes estruturais bem como sua importância como fármacos ou protótipos e como marcadores químicos de fitoterápicos.

Las algas marinas como fuentes de fitofármacos antioxidantes: [revisión] / Seaweeds as sources of antioxidant phytomedicines: [review]

Por causa del estrés oxidativo a que se encuentran sometidas constantemente, las algas marinas son organismos que presentan en su composición química cantidades apreciables de compuestos antioxidantes, entre los que se encuentran compuestos lipofílicos como ácidos grasos insaturados, clorofila y carotenos; compuestos hidrofílicos como polifenoles y vitamina C; y polisacáridos...

As seaweeds are constantly exposed to oxidative stress conditions, significant quantities of antioxidant compounds are found in their chemical composition such as lypophilic compounds like unsaturated fatty acids, chlorophyll and carotenoids; hydrophilic compounds like polyphenols and vitamin C, and polysaccharides...

Uso ético da biodiversidade brasileira: necessidade e oportunidade / Ethical use of the brazilian biodiversity: necessity and opportunity

A situação em que o Brasil e outros países em desenvolvimento se encontram hoje, de meros compradores de tecnologias importadas ou pagadores de royalties para laboratórios farmacêuticos estrangeiros, torna o processo de ampliação do sistema de saúde vigente muito oneroso ou, muitas vezes, não atende a suas necessidades específicas. O renovado interesse mundial, observado nos últimos anos, por produtos derivados da biodiversidade, tais como fitoterápicos, fitofármacos, cosméticos e suplementos alimentares, vêm estimulando investimentos de países industrializados em bioprospecção. Estas constatações devem estimular o debate, sobretudo no seio de países em desenvolvimento e detentores de rica biodiversidade e de conhecimentos tradicionais, como é o caso do Brasil, sobre a necessidade da instituição de modelos de saúdes nacionais, pautados em suas aptidões e carências, e sobre as oportunidades econômicas que o uso ético da biodiversidade apresenta.

Nowadays, Brazil and other developing countries are simple pharmaceutical technologies buyers or are only paying royalties to foreign laboratories. These facts make the public health system raise very expensive or can't put up attend to the specific necessities of these countries. The renewed global interest for natural products, such as phytotherapics, phytomedicines, cosmetics and nutraceuticals, has been stimulating industrialized countries investment in bioprospection. These evidences should stimulate the arguments, specially in developing countries, rich in natural resources and traditional knowledge, like Brazil, on the necessity of national health politics, based on their need and capacity, and on the economical opportunities that the ethical use of the biodiversity presents.

Avaliação da segurança e eficácia de Fitoterápicos / Evaluation of safety and efficacy of Herbal Medicines

Este estudo é uma revisão dos avanços no conhecimento sobre a segurança, eficácia, controle de qualidade e aspectos de regulamentação dos medicamentos fitoterápicos no Brasil. O homem sempre procurou na natureza a cura de seus problemas de saúde e sua busca de hábitos mais saudáveis, trouxe a revalorização da natureza e de terapias à base de plantas medicinais. Essa tendência mundialmente manifestada tem levado a um aumento progressivo na produção e no consumo de medicamentos fitoterápicos e produtos afins, como plantas destinadas a chás, complementos alimentares e “produtos naturais”, em geral. Em vista disso, aumentaram também as preocupações com a qualidade de tais produtos, pois são conhecidas as características desse segmento no sentido de apresentarem adulterações e falsificações. Esses problemas vem se mantendo ao longo dos anos e envolvem diversos segmentos em várias regiões do país. Visando intervir nessa situação, o Ministério da Saúde editou norma federal com intuito de disciplinar o registro e a comercialização de produtos fitoterápicos no Brasil – Portaria SVS nº 6 (BRASIL, 1995), substituída pela Resolução RDC nº 17 (BRASIL, 2000). Tais normas estabeleceram regras ao registro de medicamentos fitoterápicos e rígidos parâmetros de qualidade, segurança e eficácia terapêutica. Com a publicação da Resolução RDC 17, criaram-se amplas possibilidades de registro para medicamentos tradicionais. No entanto, formou-se um rígido esquema para o registro de produtos considerados novos, que devem ser submetidos às mesmas exigências clínicas que os medicamentos sintéticos. A legislação em vigor no país abriu precedentes para uma burocratização do sistema de aprovação de registros para produtos à base de plantas, permanecendo uma verdadeira institucionalização dos protocolos. Mesmo com toda a confusão criada em relação ao registro desse tipo de produto, o mercado entrou em franco crescimento...

This study is a review of the advances in the knowledge of safety, efficacy, quality control, and aspects of the regulation of phytomedicines in Brazil. Human beings have always sought thecure for their health problems in nature, and the search for a healthier lifestyle brought about the revaluing of nature and forms of therapy based on medicinal plants. This worldwide trendhas led to a progressive increase in the production and consumption of herbal medicines and similar products, such as plants for herbal teas, dietary supplements and "natural products"in general. In view of this, concerns about the quality of those products have also increased, as it is well known that this particular segment lends itself to adulterations and misbranding.These problems have been continuing over the years and involve a number of segments in several regions of the country. Aiming to intervene in this situation, the Ministry of Health issued a federal rule in order to regulate the registration and marketing of herbal medicines in Brazil – Directive SVS n. 6 (BRASIL, 1995), replaced by Resolution RDC n. 17 (BRASIL, 2000). These norms established rules for the registration of herbal medicines and stringent quality, safety and therapeutic efficacy parameters. With the issuing of Resolution RDC 17, broad possibilities for the registration of traditional medicines were created. However, astringent procedure was formulated for the registration of products deemed as new, which must be submitted to the same clinical requirements as the synthetic medicines. The legislation in force set precedents for increased bureacracy in the licensing system for plantbased products, and so an actual institutionalization of protocols remained. Despite all the confusion created surrounding registration of this type of product, the market boomed.However, the lack of a monitoring approach has left room for the newest way of establishing a new product without the need...

Promoção do uso racional de fitoterápicos: uma abordagem no ensino de Farmacognosia

Neste trabalho é apresentada uma experiência no ensino de Farmacognosia, cuja base principal é o estudo dos aspectos farmacoterapêuticos de fitofármacos e fitoterápicos, visando o estabelecimento de seu uso racional. São apresentados dados sobre a comercialização e ações institucionais destinadas à normatização, padronização e utilização racional destes produtos no mundo, com propostas e condutas na prática farmacêutica para aquisição e dispensação adequada de fitoterápicos.

In this paper we present a pharmacognosy teaching experience which focuses mainly on the pharmacotherapeutic aspects of phytomedicines and drugs from natural sources aiming their rational use. World commercial data and institutional actions destined to provide normalization, standardization and rational use as well some propositions for the acquisition of these products and patient counseling are presented.